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The Seismic Stratigraphy, Crustal Structure, Volcanic and Sedimentary History of the East Mariana and Pigafetta Basins of the Western Pacific

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The Seismic Stratigraphy, Crustal Structure, Volcanic and Sedimentary History of the East Mariana and Pigafetta Basins of the Western Pacific University of Rhode Island DigitalCommons@URI Open Access Dissertations 1992 The Seismic Stratigraphy, Crustal Structure, Volcanic and Sedimentary History of the East Mariana and Pigafetta Basins of the Western Pacific Lewis Julius Abrams University of Rhode Island Follow this and additional works at: https://digitalcommons.uri.edu/oa_diss Recommended Citation Abrams, Lewis Julius, "The Seismic Stratigraphy, Crustal Structure, Volcanic and Sedimentary History of the East Mariana and Pigafetta Basins of the Western Pacific" (1992). Open Access Dissertations. Paper 413. https://digitalcommons.uri.edu/oa_diss/413 This Dissertation is brought to you for free and open access by DigitalCommons@URI. It has been accepted for inclusion in Open Access Dissertations by an authorized administrator of DigitalCommons@URI. For more information, please contact [email protected]. THE SEISMIC STRATIGRAPHY, CRUSTAL STRUCTURE, VOLCANIC AND SEDIMENTARY IBSTORY OF THE EAST MARIANA AND PIGAFETTA BASINS OF THE WESTERN PACIFIC BY LEWIS JULIUS ABRAMS A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN OCEANOGRAPHY UNIVERSITY OF RHODE ISLAND 1992 DOCTOR OF PIIlLOSOPHY DISSERTATION OF LEWIS ruuus ABRAMS APPROVED: Dissertation Committee Major Professor --~~µ..l..,_~:...._j~~:.::....:...;~;e==----- UNIVERSITY OF RHODE ISLAND 1992 ABS1RACT In the following investigations regional multichannel seismic reflection and sonobuoy refraction data have been used to identify a site where Leg 129 of the Ocean Drilling Program (ODP) successfully drilled and recovered Jurassic material for the first time in the Pacific Ocean. Prior to drilling first-order stratigraphic relationships and crustal strUcture were determined. The sedimentary and volcanic history of the East Mariana Basin (EMB) and Pigafetta Basin (PB) were then inferred with emphasis on defining the extent (lateral as well as vertical) and type of deep sea volcanic provinces (sills/flows and or volcaniclastics) in this part of the western Pacific . The successful completion of ODP Leg 129, resulting in the first and only holes to penetrate igneous basement in the EMB and PB, allows the calibration of our regional multichannel seismic site surveys and the extrapolation of drilling results throughout these oldest Pacific basins. Our study indicates that mid Cretaceous flows/sills overlie Jurassic/ Early Cretaceous sediments and oceanic crust throughout an area - 500,000 km2 in the EMB and the southeast PB. Jurassic age oceanic crust and overlying upper Jurassic - lower Cretaceous pelagic sediments unquestionably exist at Site 801 and extend semi­ continuously between Site 801 and Site 800. A "Rough-Smooth" Horizon B boundary marks the termination of continuous mid-Cretaceous volcanic overburden. Volcanogenic turbidite sequences of varying thicknesses and ages are ubiquitous features of both basins. The Ogasawara Fracture Zone, Magellan Seamounts and associated flexural moat separate the PB from the EMB and influence the source and distribution of this redeposited material. This study places constraints on the depth to basement and crustal thickness in these oldest ocean basins which, when coupled with recently acquired heatflow measurements (Lister et al., 1990; Stein and Abbot, 1991), favor a time-varying heat flow model as a possible explanation for the observed divergence of heatflow and depth versus age from that predicted by a simple cooling boundary layer. These observations are consitent with those compiled in Larson (1991a,b), where increased mantle temperatures due to vigorous global plume activity are rapidly initiated at approximately 124 ma and gradually decrease toward 80 ma. ACKNOWLEDGEMENT I am grateful to my major advisor Roger Larson for inviting me along for the final stages of the "·quest for the Jurassic Pacific". After jumping off the RIV Fred Moore as it began to sink dockside in the harbor of the Micronesian island of Pohnpei and as Roger, Yves Lancelot, Tom Shipley et al., headed into the lagoon for "Joy" island, I thought then as I do now, that this is really much more exciting than graduate school is supposed to be. I am thankful to Roger for expressing his confidence in my ability by allowing me to participate as a colleague during the planning and real time decision making during the MCS and drilling expeditions to the western Pacific. I would al~o like to thank Roger, Tom Shipley and Yves Lancelot for their guidance and friendship during our adventures in the western Pacific and in the laboratory at the Institute for Geophysics in Austin (UTIG) and at the Institut de Physique du Globe, Strasbourg (IPG). Tom Shipley was especially helpful with his insights, suggestions and many reviews of the manuscripts in this dissertation. This dissertation has benefitted substantially from the comments and suggestions of my Ph.D. committee; Roger Larson, Bob Detrick, Reinhard Frohlich and Jeff Fox and I thank Dan Murray for acting as chairman of this committee. In addition, Jeff Fox generously allowed the use of his laboratory facilities and his extensive reference collection. A great deal of effort was made on behalf of myself and this project during the processing of nearly 8000 km of MCS data by Steffen Saustrup, Mark Wiederspahn, Patty Ganey at UTIG and Marc Schaming, Jacques Renault, Cecille Pourcellot and Roland Schlich at IPG, Strasbourg and Jim Dolan at GSO/URI. I am indebted to John Mutter who provided free use of the L-DGO seismic processing facilities and to John Diebold and Emilio Vera who provided software (JDSEIS) and much advise concerning sonobuoy analysis. Rob Pockalny, who actually received a Ph.D. las t year, continues to iv be a pretty good option quarterback and for "bread and butter right", two intramural football championships and a fake beach volleyball - go camping ploy, I thank him. My family has given me their enthusiastic support throughout my graduate school career and through every endeavor that I have chosen to pursue, without their help I would not have had the luxury of achieving a Ph.D. I am especially thankful for the now "Dr." Nancy Grindlay, who, even though she got married, found the time to review and discuss these manuscripts and provide continuous support and encouragement.. .if you know what I mean. v PREFACE The majority of the seismic reflection/refraction data analyzed in this dissertation were collected on two separate expeditions to the western Pacific aboard the RIV Fred Moore in the fall of 1987 and aboard the N/O Le Suroit in the fall of 1989. During these cruises, the first multichannel seismic experiments in this area of the western Pacific were conducted. The oceanographic scientific community has, for over 20 years, been convinced of the importance of examining the potentially oldest oceanic crust left in-situ on the planet as well as the overlying sediments deposited in the Jurassic super ocean at the time before the complete breakup of Pangea. The ultimate goal of drilling and recovering Jurassic age oceanic crust and overlying sediment in order to piece together the volcanic, sedimentary and environmental history of the oldest oceans and ocean basins was thwarted by the apparently ubiquitous shallow cherts or massive younger basalt sills/flows which were overlying oceanic crust. Eight scientific drilling expeditions beginning in 1969 on DSDP Leg 6 were devoted to the "Quest for the Jurassic Pacific" but were unsuccessful. Thematic panels were, to say the least, "a bit gun shy" at the prospect of devoting any further drilling expeditions to this quest, however, the initial results of the work presented in this dissertation provided convincing evidence that oceanic crust in restricted areas of the far western Pacific could be reached with available drilling technology. Three months after we collected the last of our MCS data, Jurassic material was drilled and brought on board the JO/DES Resolution during ODP Leg 129. This dissertation is presented in manuscript format and consists of three manuscripts with an appendix which when combined, represents the most comprehensive study to date of the seismic stratigraphy, sedimentary history and crustal structure of the oldest Pacific basins. I am lead author on manuscripts one and two and aco-author on the third manuscript. vi Manuscript I "Cretaceous volcanic sequences and Jurassic oceanic crust in the East Mariana and Pigafetta Basins of the western Pacific" has been submitted for publication in an American Geophysical Union Monograph entitled "The Mesozoic Pacific", M. Pringle and W. W. Sager editors. Manuscript II "The seismic stratigraphy and sedimentary history of the East Mariana and Pigafetta Basins of the western Pacific" has been submitted for publication in the Ocean Drilling Program Leg 129 Scientific Results Volume, R. L. Larson and Y. Lancelot editors. Manuscript ID "Comparison of laboratory and logging data from Leg 129 and the inversion of logs to determine lithology" has been submitted for publication in the Ocean Drilling Program Leg 129 Scientific Results Volume, R. L. Larson and Y. Lancelot editors. The co-authors for the fust two manuscripts are Roger Larson (GSO/URI), Tom Shipley (Institute for Geophysics, University of Texas, Austin), and Yves Lancelot (Laboratoire de Geologie du Quaternaire, CNRS, Marseille, France). The lead author on the third manuscript is Andrew Fisher (Ocean Drilling Program - Texas A&M University) and William Busch (Department of Geology and Geophysics, University of New Orleans) is a co-author. Although not included as part of my dissertation, I made contributions to, and am ·co-author on, several other publications which relied on the data from the cruises mentioned above as well as two reflection/refraction experiments conducted in the Nauru Basin, western Pacific'. These cruises were conducted on the N/O Charcot (Spring 1987) and RIV Thomas Washington (Winter 1988-89). Except for the cruise aboard N/O Charcot, I participated in all phases (proposal - data acquisition, processing and interpretation - publication of the results) of the three MCS and one drilling expedition to the western Pacific.
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